An image-forming device comprising, for example, a polarizing filter, a retroreflection prism, and a retardation film has been proposed. With this image-forming device, a real image representing a display image is formed at a position that is in plane symmetry to an emission point of display light representing the display image with respect to the polarizing filter. Incidentally, the retroreflective prism includes a flat front surface and an uneven back surface. Of light emitted from a display, reflected by a half mirror, and made incident on the retroreflective prism, the light which has reached the back surface is retroreflected, but the light reflected from the front surface forms an image at a position different from where the retroreflected light forms an image. Further, the light reflected from a surface of the retardation film similarly forms an image at a position different from the retroreflected light. Accordingly, separately from the actual image formed by the retroreflected light, the so-called ghost is visually recognized which may cause deterioration in display quality. In addition, since light which is emitted from the display and is reflected on the surface of the retroreflective prism directly without being transmitted to the half mirror also does not contribute to display of the real image, the display quality may be deteriorated.